How to Wait 5 Seconds Before Executing the Next Line in JavaScript?

Wait 5 Seconds Before Executing Next Line

In JavaScript, the setTimeout() function schedules a function to be executed after a specified number of milliseconds. However, it does not halt the execution of the code, meaning that the next line of code will be executed immediately after the setTimeout() call, regardless of the specified delay.

Your Code

Your code aims to wait 5 seconds before checking if newState is equal to -1. However, since setTimeout() does not block the code, the checking happens immediately, before the 5-second delay occurs.

Solution

To achieve the desired behavior, you need to use a mechanism that can pause the execution of your code for 5 seconds. There are two modern approaches you can consider:

1. Async/Await Syntax (Browser Only)

ES6 introduced the async/await syntax, which allows you to write asynchronous code in a more synchronous style. By marking your function as async, you can use the await keyword to pause execution until a promise is resolved.

<code class="javascript">const delay = ms => new Promise(resolve => setTimeout(resolve, ms));

const stateChange = async newState => {
  await delay(5000);

  if (newState === -1) {
    alert('VIDEO HAS STOPPED');
  }
};</code>

2. Timers/Promises Module (Node.js Only)

In Node.js 16, the timers/promises module provides a promise-based version of setTimeout. This allows you to pause execution and wait for the delay to complete before continuing.

<code class="javascript">import { setTimeout } from "timers/promises";

const stateChange = async newState => {
  await setTimeout(5000);

  if (newState === -1) {
    console.log('VIDEO HAS STOPPED');
  }
};</code>

Both of these approaches will ensure that the code execution is halted for 5 seconds before the newState check is performed.

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